The correct answer is B) A socket wrench with an 18-inch long 3/4-inch drive extension. To manually rotate the GE LM2500 gas turbine engine, a 3/4-inch drive socket wrench with an 18-inch long extension is the appropriate tool. This is because the large size and weight of the LM2500 engine requires a more robust and longer socket wrench to apply the necessary torque to rotate the engine manually. The 3/4-inch drive provides greater torque capacity compared to the 1/2-inch drive options in the other answer choices. The other options are incorrect because they either use the wrong drive size (1/2-inch instead of 3/4-inch) or do not provide the necessary length (18 inches) to effectively rotate the large LM2500 engine.